Portable storage device



FIG. 1 is a perspective view of a portable storage device showing our new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof;

FIG. 8 is a perspective view thereof taken from a different angle;

FIG. 9 is a perspective view showing a cap of the design being rotated; and,

FIG. 10 is another perspective view showing the cap of the design being rotated.

The broken lines depict portions of a portable storage device in which the design is embodied that form no part of the claimed design. 

CLAIM The ornamental design for a portable storage device, as shown and described. 